3D printing in medicine最新文献

Background: Both outsourcing virtual surgery planning and 3D printed splint fabrication have become the standard in the field of orthognathic surgery. In-house (IH) adaptation of these presurgical operations requires compliance with regulatory bodies when designing and manufacturing medical-grade products. The purpose of this study is to evaluate the dimensional accuracy of IH 3D printed orthognathic surgical splints within a hybrid workflow for externally designed splints.

Materials and methods: An in vitro study was conducted utilizing an outsourced (OS) orthognathic surgical splint file from a previously treated patient. The control group included the splint's original standard tessellation language (STL) file. Experimental groups included: splint (a) milled with zirconia, (b) 3D printed on a Phrozen 4 K (commercial printer), (c) 3D printed on Formlabs 3B+ (Formlabs 3B + have track record of having FDA cleared materials and workflows in dental applications and have potential materials that could be used for IH manufacturing for orthognathic splints upon further testing and FDA clearance). Surface area analysis was performed using 3-Matic (Materialise© Mimics Software) to generate root mean square (RMS) values between digital copies of the splints and their corresponding original STL files.

Results: The RMS error in equipment processing and analysis was measured at 0.10 mm. Accounting for this error, the 3D-printed splints exhibited an average RMS of 0.20 mm for both the Formlabs 3B + and the Phrozen 4 K. No statistically significant difference was found between splints from different printers or replicas.

Conclusion: This study presents a verification process for providers to verify the geometric stability and reproducibility of their IH-printed orthognathic splints (RMS 0.20 mm). Clinicians may find this study useful when crafting a regulatory-compliant process for the IH manufacturing of OS orthognathic surgery splints.

Background: Dropped Head Syndrome (DHS) is a neurological condition characterized by severe head and neck muscle atrophy, leading to difficulties in maintaining a straight gaze and experiencing severe neck pain during daily activities. Standard off-the-shelf cervical orthotic devices (Neck Collars) often fail to provide adequate support for patients with DHS. This feasibility study aimed to develop and implement a novel feedback-incorporated workflow for creating personalized 3D printed (Powder Bed Fusion) cervical orthotic devices for six DHS patients with varying pathologies.

Case presentation: A tailored workflow was devised and executed to produce bespoke 3D printed cervical orthotic devices for 6 DHS patients. The effectiveness of the collars in supporting patients during activities and reducing neck pain was assessed quantitatively and qualitatively using validated patient support questionnaires, Neck Disability Index, Visual Analog Score for Neck Pain, Global Cervical Angles (GCA), and Vertical Chin Brow Angles (VCBA) before and after intervention. Various clinical and design parameters were analysed to evaluate the collars' efficacy in supporting patients and reducing neck pain. Patients exhibited an increase in GCA and a decrease in VCBA when using the collars as compared to their previous condition without those. The Visual Analog Score for Neck Pain decreased over the 6-month follow-up period, indicating positive implementation of the bespoke collars.

Conclusion: The personalized design and functionality of the 3D printed collars significantly improved patients' quality of life, representing a significant advancement in rehabilitative and supportive healthcare interventions. This pilot study lays the groundwork for further large-scale cohort studies.

Percutaneous dilatational tracheostomy is an established technique for securing the airway in critically ill patients. One of the most common complications is bleeding around the incision or after injury to major vessels in anatomic proximity.We report a case in which a thrombocytopenic patient experienced life-threatening bleeding during the procedure at the bifurcation between segmental bronchus 9 and 10, apparently caused by an unrecognized guide wire-induced mucosal lesion. Immediate extensive bronchoscopy and hemostatic interventions were required to ensure oxygenation. To better illustrate this complication, a patient-specific (1:1) three-dimensional model of the patient's bronchial system was subsequently created using a 3D printer. In conclusion, 3d printing can help to visualize uncommon complications during intensive care interventions. It is recommended to advance the guide wire the guide wire only until the tracheal carina under bronchoscopic control.Word count: 135.

Tibiotalocalcaneal (TTC) arthrodesis treatment using intramedullary nails faces significant challenges due to inadequate bone integration and mechanical stability. This study developed a novel 3D-printed long titanium TTC intramedullary nail incorporating diamond lattice structures and differential thread leads to enhance biological fixation and compression. Four 3D-printed TTC nails (5 mm diameter, 70 mm length) with solid (TTC 1), lattice structure (TTC 2), lattice with longitudinal ribs (TTC 3), and lattice with both longitudinal and transverse ribs (TTC 4) were designed and manufactured. The lattice region featured a diamond array (70% porosity, 650 μm pore size, 1.2 mm unit length) with 2.5 mm thickness surrounding a 2.5 mm solid core. Static four-point bending tests assessed mechanical strength following ASTM F1264 protocols. Six skeletally mature Yorkshire pigs underwent TTC arthrodesis using TTC 1, 2, and 4 designs. Outcomes were evaluated using radiographic imaging and micro-CT analysis at 12 weeks post-surgery. All 3D-printed nails demonstrated acceptable precision with errors below 5% for straightness, circularity, and pitch distance. Mechanical testing revealed fracture strengths of 2387.33 ± 32.88 N, 435.00 ± 50.00 N, 849.17 ± 63.98 N, and 1133.67 ± 81.28 N for TTC 1-4, respectively. The differential thread design achieved significant compression ratios (81-82.5%) at fusion sites. Micro-CT analysis showed significantly higher bone formation in lattice designs (TTC 2: 145.37 ± 37.35 mm³, TTC 4: 137.81 ± 9.52 mm³) compared to the solid design (TTC 1: 28.085 ± 3.21 mm³). However, TTC 2 experienced two implant fractures, while TTC 4 maintained structural integrity while promoting substantial bone growth. This study concluded that titanium 3D printing technology can be applied for manufacturing long TTC intramedullary nails with surface lattice design but reinforcing ribs need to be added to provide enough mechanical strength.

Background: Meniscal allograft transplantation (MAT) restores knee function by replacing a damaged or absent meniscus with a healthy allograft, helping to preserve joint stability, distribute the load, and reduce cartilage degeneration. However, traditional 2D imaging techniques fail to fully capture the knee's complex three-dimensional anatomy, making accurate surgical planning challenging. Computed Tomography (CT)-based 3D printing offers a patient-specific solution by generating anatomically precise tibial models, allowing for enhanced preoperative planning. This is particularly valuable in complex cases involving tibial osteotomy and anterior cruciate ligament (ACL) reconstruction, where precise tunnel positioning is critical to avoid tunnel convergence and ensure optimal graft integration.

Case presentation: We present a case study and methodology demonstrating the generation and application of 3D-printed tibial models to assist in MAT, ACL reconstruction, and tibial osteotomy. High-resolution CT scans (slice thickness < 1 mm) were processed using D2P software to create a full-scale 3D model, which was printed using Hyper PLA filament. The 3D-printed model was provided to the tissue bank to optimize meniscal allograft selection and was integrated into preoperative planning to precisely determine tibial tunnel locations and angles, preventing overlap between MAT, ACL tunnels, and the osteotomy site. Intraoperatively, the model served as an accurate physical guide, facilitating osteophyte removal, guided tunnel drilling, and precise meniscal graft placement. Its use improved graft sizing accuracy minimized tunnel convergence, and allowed real-time intraoperative adjustments, which can improve surgical precision and decision-making.

Conclusions: The integration of patient-specific 3D-printed models into surgical planning and execution may improve accuracy and efficiency in complex MAT procedures that also involve tibial osteotomy and ACL reconstruction. These models offer detailed anatomical reference points that facilitate more precise graft selection, tunnel placement, and intraoperative decision-making. However, further studies are needed to validate their dimensional accuracy, evaluate clinical outcomes in larger cohorts, and determine their feasibility for routine use in orthopedic practice.

Background: Puncture training with simulation models has emerged as a critical method for transmitting puncture skills, improving success rates, and minimizing injuries. Yet, obstacles such as proper material for ultrasound guidance, restricted options of 3D printing resources, and available substances to simulate human skin and muscle still hinder the production of simulation models that closely replicate clinical practice. This study aimed to develop a selective laser melting (SLM), 3D-printed simulation model that replicated the spine and skin contours of patients with spinal scoliosis.

Methods: The 3D models of the scoliotic spines were developed from 3D reconstructions of high-resolution, computed tomography images from patients with spinal scoliosis, while the models of the skin to the bone structure were constructed based on the 3D reconstructions of the skin contours. SLM technology was used to print 3D models of the patients' spines. Gelatin casting was implemented to simulate the patients' skin and muscle tissues and to meet ultrasound anatomical requirements. Practical puncture training, which closely resembles clinical puncture practice, was then carried out to validate the effectiveness of the model. Improvements in proficiency and confidence in performing ultrasound-guided punctures after the simulation-model training were evaluated using the paired sample t test.

Results: This research utilized 3D digital modeling, SLM 3D printing technology, and gelatin casting to establish simulation models of patients' spines and skin contours impacted by spinal scoliosis. The use of medical grade stainless steel material for modeling the spine and gelatin for skin and muscle tissues ensured the model had superior ultrasound anatomical properties. After the simulation training session, participants' proficiency and confidence in both ultrasound-assisted positioning and real-time guided puncture showed significant improvement, demonstrating the effectiveness of the simulation training model.

Conclusions: The simulation model closely mimicked real clinical situations and was an effective training tool for medical professionals. Furthermore, these findings demonstrated the potential of 3D printing technology in developing simulation models that closely replicate real-world clinical scenarios and may have significant implications for medical education and training.

Background: Double outlet right ventricle with remote interventricular communication presents significant surgical challenges. Traditional imaging often fails to provide the detailed, three-dimensional anatomical insights required for complex cases. Advancements in three-dimensional (3D) printing offer a valuable tool for preoperative planning and decision-making.

Cases: In the first case, a 5-year-old with double outlet right ventricle and remote interventricular communication underwent a Glenn procedure with anticipated univentricular repair. 3D printing revealed the potential for enlarging the communication, leading to a one-and-a-half ventricle repair. The second case involved a 2-day-old infant with double outlet right ventricle, aortic arch interruption, and remote communication. At one year, 3D modelling enabled a successful left ventricle-to-aorta baffle.

Conclusion: These cases underscore 3D printing's role in improving precision, reducing complications, and potentially lowering costs in managing complex congenital heart disease.

Background: Xenograft mouse models play an important role in preclinical cancer research, particularly in the development of new therapeutics. To test the efficacy of a combination therapy consisting of radiation and new drug candidates, it is crucial that only the tumor area is irradiated, while other parts of the body are shielded. In this study, a 3D-printed radiopaque back shield was designed for tumor-specific irradiation and evaluated in a xenograft mouse model.

Methods: Different radiopaque materials were initially tested for their shielding properties using the Multirad 225 X-ray irradiator and the most suitable material was used for printing a back shield with a tumor site-specific opening of the cover. Tumor bearing mice were irradiated four times with a dose of 3.5 Gy. To evaluate proper body shielding, blood samples, spleens and bone marrow were examined at the end of the experiment.

Results: A tungsten filament was identified to be most efficient for shielding and used to 3D print a pie-slice-shaped back shield with a tumor-site specific opening, while polylactic acid was used to print a scaffold that ensured proper positioning of the shield. The simple design allowed cost-efficient and fast 3D printing, easy handling and individual modifications of the tumor site openings. In terms of animal safety, the product provided sufficient shielding in the low-dose irradiation protocols of xenograft mice.

Conclusion: The custom-designed 3D-printed tungsten back shields provide proper shielding of the animals body and allow for subcutaneous tumor irradiation under standardized conditions.

Background: The importance of reducing error rates in invasive procedures has led to the development of teaching phantoms. In collaboration with surgeons and engineers at the University Hospital of Leipzig, a new 3D-printed simulation model for external ventricular drainage was created. This model includes system-relevant components such as the ventricular system, the surrounding brain tissue and the skull bone to be trephined. The methodology for developing the simulation model is described in detail. Additionally, the system was initially evaluated by neurosurgeons using a Likert scale. Future studies are planned to assess the system's accuracy and perform comparative analyses.

Methods: The data required for analysis were extracted from medical images. The phantom consists of three components: the ventricular system, the brain mass, and the skull bone. The bone component was fabricated via 3D printing using a realistic hard polyamide, PA12. The ventricular system was also 3D printed as a hollow structure using a flexible material, Elastic Resin 50 A from Formlabs. The brain tissue was modeled via a cast gelatin mold. The cerebrospinal fluid was a water solution.

Results: The system's initial tests successfully simulated cerebrospinal fluid flow through the tube into the ventricular system. The skull can be trepanned. Additional materials are required at the drilling sites because of chip formation. A more pointed cannula than usual can puncture the ventricular system. With a concentration of 30 g/l, gelatin is a realistic imitation of brain tissue.

Conclusion: All essential components of the skull, brain and ventricle exhibit a degree of realism that has never been achieved before. In terms of its design and reproducibility, the model is exceptionally well suited for training and consolidating methods and procedures as part of a realistic training program for the placement of external ventricular drainage.

Objective: This study introduces a surgical technique involving the use of 3D-printed all-metal prostheses combined with mesh patches for the treatment of distal radial giant cell tumors, analyzing and evaluating the midterm outcomes for patients undergoing this treatment. The experience provides insights into the application of prosthesis replacement for reconstructing distal radial defects.

Methods: From January 2018 to January 2021, our center treated five cases of distal radial giant cell tumors using 3D-printed all-metal prostheses combined with mesh patches. Postoperative pain, range of motion, and grip strength were evaluated for all patients. Oncological outcomes, complications, and degenerative changes in the wrist joint were also assessed. Functional outcomes were evaluated based on the Mayo wrist score system.

Results: The average follow-up period was 40.8 months (range: 32-66months). At the last follow-up, the mean range of motion (ROM) in the affected wrists was 20° extension, 21.6° flexion, 71.2° pronation, and 50° supination. The mean grip strength on the affected side was 64.2% compared to the unaffected side, with a Mayo score of 70. There were no incidences of aseptic loosening, wrist subluxation, or infections post-prosthesis replacement, although two cases presented with distal radioulnar joint dislocation. Of these, one case demonstrated ulnar impaction syndrome with positive ulnar variance and lunate bone degenerative changes on the 12-month postoperative radiographs. No recurrences or metastases were observed.

Conclusion: Utilizing 3D-printed metal prostheses and mesh grafts for the treatment of Campanacci Grade III or recurrent giant cell tumors of the distal radius is an effective approach. This strategy provides favorable functional outcomes during the early to mid stages of treatment, while also maintaining a low risk of complications. The concurrent use of mesh grafts facilitates early postoperative exercise, thereby accelerating functional recovery. Moreover, the intraoperative protection or reconstruction of joint ligaments, along with precise matching of the prostheses, contributes to a reduction in the risk of complications.